Since there are no antithrombotic dose-response data available for FFR-rFVIIa in humans, we initially proposed to carry out a placebo-controlled, safety and efficacy dose-finding study assessing the effects of dosing FFR-rFVIIa vs placebo in 4 cohorts of patients each (4:1 randomization favoring active therapy) on AVG 111In-platelet deposition at the time of AVG surgical placement or replacement (primary outcome). This dose will subsequently be used in a controlled clinical trial of AVG failure. We also propose to compare the dose-response effects of FFR-rFVIIa vs placebo on post-operative changes in blood tests of thrombosis, tests of hemostasis and measured surgical blood loss (secondary outcome measures).